High-voltage cell structure



8" 7, 1951 J. D. WOOD ET AL 2,563,441

HIGH-VOLTAGE CELL STRUCTURE Filed Dec. 20, 194'? 14 Sheets-Sheet 1 101 7 20 Joseph D.wood

7, 95 J. D. WOOD ET AL 2,563,441

HIGH-VOLTAGE CELL STRUCTURE Filed Dec. 20, 194'? 14 Sheets-Sheet 2 101 1 INVENTORS Joseph D.Wood

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HIGH-VOLTAGE CELL STRUCTURE Filed Dec. 20. 194? 1 1 Sheets-Sheet 4 fig. 4b

INVENTOR Jqsepb D.Wood BYgeoflg'e W. Spicp Httmzey J Aug. 7, 5 J. D. WOOD ET AL 2,563,441

- HIGH-VOLTAGE CELL STRUCTURE Filed Dec. 20, 1947 14 Sheets-Sheei 7 INVENTOR Joseph D.Wood

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HIGH-VOLTAGE CELL STRUCTURE Filed Dec. 20, 194'? 14 Sheets-SheeVlO INVENTORS Joseph D. Wood BY O'eonge w.s |cep fittamg/J Aug. 7, 1951 Filed Dec. 20, 1947 J. D. WOOD ET AL HIGH-VOLTAGE CELL STRUCTURE 14 Sheets-Sheet 11 I \rizfi JNVENTORS Joseph D.Wood

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flttmcy/J J. D. WOOD ET AL HIGH-VOLTAGE CELL STRUCTURE Aug. 7, 1951 14 Sheets-Sheet 12 Filed Dec. 20, 194'? com onT

IN IN IWWHHH INVENTORS Joseph D. Wood O'eonge W. sfnccn ATTORNEYS.

u 1951 J. D. Wool: ETAL 2,563,441

HIGH-VOLTAGE CELL STRUCTURE Filed Dec. 20, 1947 14 Sheets-Sheet 15 r INVENTORS Joseph D.Wood BY g gohg'e W. Spleen ziA-a kjr v 11-.

ATTORNEYS.

g- 7, 1951 J. D. WOOD ET AL 2,563,441

HIGH-VOLTAGE CELL STRUCTURE Filed Dec. 20, 194'! 14 Sheets-Sheet 14 Ev MN hwd D ||l| I I II II R mm llrlllllll r I L L INVENTORS J H M 0mm &- m9: 0% 8 Joseph D.Wood O'eoP eW.S |cero (V ML) ATTORNEYS.

Patented Aug. 7, 1951 UNITED STATES PATENT OFFICE 12 Claims.

Our present invention relates to a switchboard for high voltage circuit breakers and more particularly to a switchboard specifically adapted for use in connection with a high voltage circuit breaker rated at 50,000 kva. interrupting capacity and of the general type described in our application Serial No. 721,648 filed January 11, 1947.

One of the essential elements of the type of circuit breaker disclosed in the aforesaid application is that it is made up of a number of unit assemblies which may readily be selected from standard parts which may be stocked against orders.

The switchboard for the circuit breaker also should be so arranged that the elemental parts thereof may readily be stocked to be assembled for future requirements in accordance with the particular demands of the specific switchboard to be constructed.

Heretofore, in the construction and operation of switchboards of various types including com partments, cells or housings for various kinds of circuit breakers, switchgear, instruments, transformers and other elements which go into the making of the switchboard, it has been necessary to custom build each of the switchboards and to fabricate each of the specific parts thereof from sheets, angles, bars, channels, tubes and other elements.

This has greatly increased the cost of switchboard construction since no stocking of elementary parts has previously been thought possible.

An essential object of our invention is the provision of individual separately manufactured component parts which may readily be assembled into switchboard structures of various types or for the purpose of housing specific types of switchgear permitting a radical departure in the method of fabricating switchboards and making mass production methods possible in contrast to the custom building procedure of the prior art.

Another object of our invention is the arrangement of switchboard structures composed of specific stock parts which may readily be assembled.

Another object of my invention is the arrangement of switchboards so that additional stock parts, compartment cells or other elements may be attached thereto, with provision being made for such future attachment; and even with provision for reassembly of the switchboard elements to form other arrangements after the same have been manufactured, shipped and installed.

Another feature of my invention is the provision of novel racking mechanism in connection with specific readily assemblable and readily rearrangeable switchboard structures, whereby the racking operation for the circuit breaker is accomplished by the operation of one screw and in which the circuit breaker is locked int position by the closing of the front door of the circuit breaker compartment.

Th foregoing and many other objects of our invention will become apparent in the following description and drawings in which:

Figure 1 is a cross-sectional View taken vertically front to back through a compartment or enclosure in our novel switchboard showing the circuit breaker in the operating position.

Figure 2 is a view corresponding to that of Figure 1 showing a circuit breaker in the test position.

Figure 3 is a view in perspective of an end of our novel switchboard with one of the enclosures partially broken away in order to show th various members which are welded to the side sheets.

Figure 4 is a side view of the interior portion of a side wall section adapted specifically for. the left side of a compartment. 7

Figure 4a is a vertical cross-section taken on line lid, id of Figure 4 looking in the direction of the arrows.

Figure ib is a top view of the wall section of Figure 4, partially broken away in order toshow elements below the top channel section.

Figure 5 is a side view of the interior side wall of our novel switchboard compartment structure showing a side wall particularly adapted for use on the right sid of a compartment.

Figure 5a is a vertical cross-section taken on line 5a, 5a of Figure 5 looking in the direction of the arrows.

Figure 5b is a top view partially broken away of the wall section of Figure 5.

Figure 6 is a side view of an intermediate wall section adapted to be used in place of a right and left wall section between two compartments, being used as a substitute for two combined wall sections of Figures 4 and 5.

Figure 6a is a cross-sectional view taken on line Ba, 6a of Figure 6 looking in the direction of the arrows.

Figure 6b is a top view partially broken away of the intermediate wall section of Figure 6.

Figure 7 is a plan view of the top piece or cover of one of the enclosures.

Figure 8 is a plan view of the bottom plate one of the enclosures.

Figure 8a is a front end view of the bottom wall section of Figure 8.

Figure 9 is a front elevation of the front door.

' 3 Figure 9a is an end view of the door of Figure 9.

Figure 10 is a rear elevation of the back cover of the enclosure.

Figure 10a is an end view of the back figure of Figure 10.

Figure 11 is an elevation of the isolation plate which divides the enclosure into the breaker compartment and the bus compartment.

Figure 11a is an end View of the isolation plate of Figure 11.

Figure 12 is a front view of the shutter assembly including the shutter which slides vertically in front of the isolation plate of Figure 11 and showing also the breaker guide track with part of the sides of the enclosure shown in phantom. The shutter is shown in the open or operative position and indicated in phantom in the closed or inoperative position.

Figure 13 is a side view taken just within the left side wall of the compartment showing the shutter assembly in the operative position of the circuit breaker and the circuit breaker in position within the compartment and showing also in dotted lines the position which the compartment elements assume when the circuit breaker withdrawn.

Figure 14 is a view in perspective of an assembly of several enclosures according to my invention showing the method of attaching supplementary compartments for various accessories.

Figure 15 is a plan view of the racking and indicating mechanism of our novel circuit breaker and shows the sides of the enclosure in phantom.

Figure 16 is a schematic right side view of the operating mechanism of the circuit breaker and the guide track on which it runs showing the variousinterlocking and safety features.

Figure 1'7 is similar to Figure 16 but shows the relation of the circuit breaker to the enclosure in the test position.

Figure 18 is a left side view of the indicating mechanism of our novel circuit breaker showing thetrack and racking members in phantom.

Figure 19 is a similar View to Figure 18 except that the indicating mechanism is shown in the testposition."

Referring first to. Figures 1,2, 3 and 14, our novel switchboard may comprise a number of circuit breaker enclosures represented by the two enclosures I!) and H of Figures 3 and 14 and addi tional compartments such as compartments [3 and Id of Figures 1 and 2 or compartments [Sand I5 of Figure 14. Compartments i3, i4, and it as hereinafter described may provide housings for instruments of various kinds and other auxiliary elements essential to the operation of the switchboard.

In Figures 1 and 2 we have shown side views of the interior of the compartment l0 and in Figure 3 we have shown a broken away view in perspec tive of the interior of compartment [9.

Essentially, each of the individual enclosures for specific circuit breakers of the high voltage type of the general character described in the application Serial No. 721,648, filed January 11, 1947, comprises a multiplicity of specific enclosures each for a specific purpose: Thus the compartment 10 comprises a circuit breaker enclosure I! at the front extending the full vertical height and width of the entire enclosure 18, and

extending back up to the isolation plate It, which extends from the top to bottom of the enclosure l0. Behind the lower portion of the isolation plate I8 is located the load bus compartment 2!! which is enclosed by the vertical metal sheet 2! and the horizontal metal sheet 22 which extend between the side walls of the compartment as hereinafter described. The remainer of the enclosure comprises additional compartment 23 at the rear of the entire enclosure which may contain the pot head 24 for distribution of the incoming current toindividual buses 25 which lead to individual current transformers 26 to the in. dividual stationary back disconnect contacts 2'1. The current transformer 2% also in compartment 23 is secured to the upper rear end of the isolation plate I8 in any suitable manner as, for instance, by the current transformer mounting feet 28 which in turn are bolted to the U-shaped channel brackets 29, 29 welded to the'rear of the isolation plate [8.

The upper stationary disconnect contacts 2?, usually three in number, aremounted within insulating tubes 36 secured in any suitable manner in opening 3|, 3! of isolation plate IS. The tubes 30 are provided with a front flange 32 preferably integral with the material of the insulating tube 30 which positions the front of the insulating tube 30 accurately within the openings 3|. The

- insulating tubes 30 are captured in the openings 3| of the isolation plate l8 by a securing ring 33 mountedcver the insulating tube 30 and secured in an suitable manner to the rear surface of the isolation plate I8. The lower stationary disconnect contacts 35 which match in number the upper stationary disconnect contacts 21 and are located immediately below the upper stationary dis connect contacts 27 are also mounted in insulating tubes 36 which are positioned in openings 37, 3'! of the isolation plate 18 and which areheld against the isolation plate 18 by the integral flange 38 and the securing ring 35 at the front and back, respectively, of the isolation plate IS.

The main buses iii, Gil for each of the individual '7 disconnects 35 are connected to their specific disconnect contacts by the jumper buses 41 which are covered by pre-molded slip-on tubings 32. A molded insulation bus cover 60 is provided between the lower disconnect contacts 35 and the individual jumper buses 4|. The main buses All in the compartmentiii are'also provided with slip -on insulating tubing 45. I

The utilization of pro-molded slip-on insulating tubes obviates the necessity for covering buses and 4t during manufacture; nor need specific lengths of such buses be sent out-or otherwise specially treated in order to provide the specific insulation required.

An essential element of the construction of our novel switchboard is the ability to construct the switchboard from readily available parts which may be stored. Accordingly, the individual main bus 40 and the individual jumper buses H are provided and storedwithout insulation and the individual insulating tubings G5 and 42. may-be separately stored. When the switchboard is constructed and the individual compartments laid out the main bus 4!] and jumper buses ii are out to size and then the tubing 45 for the main bus 40 and tubing &2 for the jumper buses ii are cut to appropriate size so that they may be simply slipped over the individual bus elements which they are to protect. In order to prevent the ef fects of corona discharge or other surface phenomena which may result from irregularities in the bus surface, the interior of the molded insulation tubing which is slipped on over the buses is provided with a conductive or semi-conductive surface and the cross-sectional area of the molded insulation is so arranged that the conductive 5 or send-conductive surface will be pressed into fairly tight engagement with the particular bus. As long as an eflicient contact is made at least at some-points between the interior of the molded insulation and the bus itself, defects or phenomena which would result from the utilization of the simple molded insulation without any conductive surface are obviated and the effects of corona discharge phenomena are thus obviated.

Molded insulation bus joint covers 60, 56 are placed over the connections or joints between the disconnect contacts 21 and the current transformer'jconnection extension 51. These are similar to the molded insulation cover 60 placed over the connection between lower disconnect contact 35 and jumper bus 4|.

The compartment I0, in addition to the side walls hereinafter described, includes a top wall 66, a bottom wall 31, and a front wall 68 which preferably consists of a door hinged on the left side 69 and held in place in the closed position in any suitable manner as for instance by the panel screws I9. Each front panel or door 68 is also provided with a small panel or door 62 preferably hingedly secured to the main door 58 along the left side at 63 and held closed by a lock 54. Door 62 closes the opening 63 through which control elements hereinafter described for moving the circuit breaker between the operative and the test position are accessible when the door 62 is open without requirin the opening of the entire front panel or door 68.

A safety feature is thus provided since all of the control elements both for racking the circuit breaker in and out and for testing the circuit breaker are accessible through the door 62 of the main front door or panel 58. Keeping the main front door panel 68 closed while racking the circuit breaker in or out or while testing it provides an eflicient protection for the operator in case any fault or unintended current is present within the compartment during any portion of the racking in or out or testing procedure.

The circuit breaker I is provided with a plurality of elements as described in the heretofore mentioned application Serial No. 721,648 filed January 11, 1947, and as above-described may be provided with control contact shown as contact 'II in the above identified application which may contact with the stationary control contacts I6 both in the fully operative and in the test position of circuit breaker. The stationary control contacts IE on the side of the compartment are connected in a suitable manner as by a cable to the terminal blocks I4 for outgoing control circuits which terminal blocks I4 are located within the enclosing steel cover I5 at the rear bottom of the rear compartment 23. Suitable Wiring connections are made through troughs along the side walls which are herein described.

The circuit breaker I0 is also provided with a grounding contact (not shown) which engages the grounding connection 1'! which is in turn supported by the isolating barrier IB. The ground connection 11 is sufliciently long so that the circuit breaker I0 is completely grounded in every position of the breaker within the front compartment I'I until the circuit breaker I0 is to be fully withdrawn and has been moved outward beyond the test position for withdrawal purposes.

The circuit breaker I0 is provided with upper disconnect contacts 80 and lower disconnect contacts 8 I. The upper disconnect contacts 80 enter the upper tubes 30 to engage the stationary dis- 6 connect contacts 21 and the lower disconnect contact 3| entering the tubes 33 to engage the lower disconnect contacts 35. The disconnect contact 34, 34 elements may have the general construction shown in application Serial No; 721,648 assigned to the owner of the present invention but may have any suitable disconnect structure.

The circuit breaker I0 is also provided with racking mechanism at 85 which is intended to cooperate with complementary racking mechanism in the front compartment IT. This rack ing mechanism is of the type described in ap-' plication Serial No. 721,648.

The base I00 of the circuit breaker is provided with three wheels IOI, I01, I02 for riding in appropriate guides at the bottom of the compartment II; the circuit breaker I0 is also provided with intermediate side wheels I03, I03a for riding on the intermediate tracks described specifically in connection with Figures 4, 5, and 6.

In Figure 2 the circuit breaker I0 has been shown racked out to the test position with the disconnect contacts and 8| of the circuit breaker I0 disconnected, respectively, from the stationary disconnect contacts 21 and 35 in the compartment. The control contacts II of the circuit breaker are in engagement with the stationary control contacts I6 in the interior of the circuit breaker compartment and the grounding contact T! of the circuit breaker is still in enengagement with the grounding bus 18 in the compartment.

With the control contacts "IE engaged various control aspects of the circuit breaker may be tested while nevertheless no current is passing through the main contacts 80, 8| of the circuit breaker owing to the fact that the main disconnect contacts 34, 34 have been separated. Of course, it is necessary to unlock the lock 64 and open the small panel of door 62 covering the opening 55 in order that the rack-out mechanism and the closing handle member I I0 of the circuit breaker might be accessible through or actually extend outside of the front panel 68 for operation of the circuit breaker and the rack-out mechanism. In the test position the closing handle member I It extends outside of the front panel 68 and the small panel or door 62 in opening 55 opens sufiiciently to permit full operation of the handle H0 in order to test the circuit breaker I0 properly.

The various wall and track arrangements shown and indicated in Figures 1, 2, and 3 will become clearer from an examination of Figure 4 which shows a wall for the left side of a compartment when the compartment is faced from the front; Figure 5 which shows an almost identical wall for the right side of the compartment and Figure 6 which shows an intermediate wall which combines all the aspects of Figures 4 and 5 for a left-right wall or intermediate wall to be used between two compartments when a multiplicity of compartments are used.

Referring first specifically to Figure 4, the left side wall I20 is divided essentially into three sections. Section I2I is the front vertical half of the wall which defines the left side of enclosure H of the entire compartment I9. Section I22 of the wall is the portion of the wall which defines enclosure 20 of the compartment I0. Section I23 of the wall is the section which defines enclosure 23 of the main compartment.

As previously pointed out, enclosure I'I defined in part by portion I2I of side wall 20 is for the g" circuit breaker. Enclosure 23 is defined in part by section I23 of the side wall in which the pot head 24, current transformer 26' and upper stationary disconnect contact assembly are mounted. Enclosure defined in part by portion I22 of the side wall of Figure 4 is the portion in which the lower disconnect contact assembly and bus assembly are housed.

The vertical isolation plate It of Figures 1, 2 and 3 is supported between opposite side- Walls of Figures 4 and 5 by the vertical brackets I of Figure 4, the left-hand side wall and ISI 01" Figure 5 the right-hand side wall. The other section I2Ia, i22a, and i230. of the-right-hand side wall of Figure 5 correspond to the similarly numbered sections of Figure 4 already described and cooperate with these sections inorder to define the enclosures of the compartment above-mention'ed.

The transverse housing members 2i and 22 which define the lower disconnect compartment 20 are supported between brackets or flanges I32, I33 of the left-hand side wall of Figure 4 and the similar flanges or brackets I'32d, I33a of the right-hand side wall of Figure 5. The two side walls and the panels or sheets 22 and 2i thus form the complete enclosure for the lower disconnect contact assembly and the main buses assembly.

' Side wall sections 522 and 522m of the left-hand and right-hand side walls 720 and area, respectivelyiFigures 4 and 5) are provided with the rectangular openings E and I35a in order to provide a passageway for the main bus run and their supports from one compartment or enclosure to the neirt.

The entire side wall sections I20, I20a are preferably made of a single sheet to which the various brackets, channels and troughs are welded or secured in any suitably manner.

The stationary control contact members 76 at the lower portion of the circuit breaker compartment I! are supported in any suitable manner from the side walls as by the brackets and flanges I40 and MI of the left-side wall I26 of Figure 4 and E4011 and Mia of the lower front end of the right side wall i2ta of Figure 5.

The side sheets or walls 20, I20a of Figures 4 and 5 are each provided with atop channel member I58 and IEEla, respectively, which members each act as an upper stiffening piece. Members I50, la also act as troughs for any wires which may be required for control or other purposesor for actuation or connection to instruments; and the elements I50, lfilla also act as a support for the top plate 65 hereinafter more specifically described in connection with Figure '7.

Similar trough like channel members of inverted Ushape cross-section I5i and I5Ia are provided for the bottom edge of the side walls I26, I2iia for Figures 4 and 5. These members also act as stiffening pieces; as pointed out in connection with the upper members of similar conformation they may act as troughs for control or other wiring connections for various elements of the circuit breaker or instruments or attachments connected thereto; and they also act as a brace which facilitates the securement of the side pieces to the bottom wall 57 of Figure 8.

The back end of each or" the walls I20 and I20a of Figures 4 and 5 is stifiened by the vertical channel members 555 and Ia, respectively, having the outwardly extending flanges I56, I57 for the side wall 520 of Figure 4 and I56a and I-5la'for the side wall I200, of Figure 5; the said flanges being welded or otherwise secured in any suitable manner to the side walls I20, I20a.

These members act not only as stiffening pieces where required but also act as a trough for control wires or connections to various elements of the switchboard.

The front of each of the-walls I20 and I20a is further stiffened by the re-entrant flange I60 for wall iii of Figure 4 and Ifita for wall I 20a of Figure 5 and the back of each of the walls is similarly stiffened by re-entrant flanges IBI of Figure 4 and Him of Figure 5. The flanges I60 and Ifiila also serve as an appropriate support for the front panel or door 68.

The horizontal flange channel members I and i70a are provided, respectively, for side walls I20 and HM in the lower sections I2I, I2Ia, respectively, of these side walls. These channel members are provided, respectively, with flanges I'll, I7! and Illa, IIIa by means of which the channels I70, I700; are welded or secured in any other suitable manner to the Side walls. The channels Il'ii, Ilda act as stiffening pieces for the side walls as well a troughs through which wires or other connections may be made to various elements of the switchboard; the channels I70, I70a are, however, especially provided in this location to act as a support for tracks which carry wheels i075, andltfi of the circuit breaker in order to support the circuit breaker in the compartment. The track members, hereinafter described, which are supported by the channels I70, 170a are, so arranged that when the circuit breaker is in the compartment the wheels E03 and 04 riding on the said tracks cause the lower wheels IOI, I02

to lift from the bottom floor 67 of the compartment.

The smaller vertical channels I and I76 for side wall IZil of Figure 4 and Elsa and l76a for side wall I200. of Figure 5 are secured in any suitable manner as by spot welding the flanges I78, I79, I78a,-il9a thereof to the said side Walls. These channels E75, I 76 extend between the horizontal channels I70 which support the tracks and the lower horizontal channel lei at the base of the side wall and act as a stiffening means for further rigidifying track I70 in order to assist in the support of the circuit breaker 70 which rides on a track supported by the channel I70.

Eachoi the side walls is also provided with the bracket member iBQ secured in any suitable manner, as, for instance, by welding and which provides a support for the pot head 24. Each of the side members is also provided with an openingi83, Itia, respectively, for the side walls I20, I200. of Figures 4 and 5 in order to provide a passage for the grounding bus (not shown).

The lower ends of channels W5 and i55a of Figures 4 and 5 are each provided with an opening E88, I a, respectively, in order to provide for means of entry of control or other connecting wires which may pass through the channels I55 and idea. Strap 88 across the vertical channel members I55, E5500 is provided for rigidity. The side wall members E23, IEfia of Figures 4 and 5, respectively, are preferably used'at the end or as the end walls of any switchboard.

The walls are-provided with the openings shown and described so that additional sections may be added where required. But in order to give the outer side walls of the switchboard a finished appearance and to exclude dust from any of the openings which do not have to be utilized, a finishing piece consisting of a flat sheet E90, seen in Figure 3, is provided which may be secured in 9 any suitable manner as by the screws 19H over the outside of the side wall I20 or |20a of Figures 4 and 5, respectively.

Where an additional enclosure is later to be added to the particular side wall, then the sheet ISO is removed; an additional side wall member of the form of Figures 4 or 5, as the case may be, is secured in any suitable manner against the existing side wall member with the openings aligned and the additional compartment is added.

Where, however, a multiplicity of compartments are constructed simultaneously for a partircular switchboard, then in order to obviate the necessity for individual right and left hand wall for the intermediate walls between two compartments, my invention contemplates the provision of a special intermediate wall member I201) of Figure 6.

The intermediate wall member [261) of Figure 6 has all of the elements previously described in connection with Figures 4 and 5, one side of the intermediate wall i261) carrying the elements shown in Figure 4, and the other side carrying identical elements, the said elements being arranged as shown in Figure 5. The reference numbers previously applicable to Figure 4 have been. applied to the view of Figure 6 since the elements shown in Figure 6 are the left hand wall elements identical in form and arrangement with the. elements of Figure 4. The right hand wall elements visible in Figures 6a and 61) have been consisting of a large number of compartments arranged adjacent to each other, cuts down the cost of material and assembly appreciably.

The wall members of Figures 4, 5, and 6 are so arranged that they may be readily stocked and assembled in connection with the other wall elements of Figures 7, 8, 9, 10 and 11 hereinafter described.

All of the wall elements, including the wall elements of Figures 7- to 11 as well as the wall elements already described are so contructed that they comprise flat or relatively flat sheets which may be stored without consumption of any unnecessary space and, in fact, occupy little more space than that which would be required for flat sheet stock which heretofore was used to custom build or form each of the circuit breaker or other switchboards when an order was received.

By this means, therefore, great economy in opera-tion is achieved because mass production methods are permitted and assembly operation may bemade from stock rather than by hand operations from individually formed sheets.

The circuit breaker enclosure is provided with a top plate 65 (Figure '7) having recesses 200 on each side in order to provide clearance for the vertical channels I55, [55a of Figure 4. and 5. The top plate 55 is also provided with the opening 2M registering with the chimney 252 above the are chute. Chimney 202 is more particularly shown in Figure 3 and comprises a pair of insulating side plates 203, 204 supported on an in sulating cross piece 255 carried at the front upper end of the isolating plate 88. The insulating side plates 283, 28 are interbraced by the insulated cross bar 285 and are also supported by the upper bracing bars 201, 268 which extend between the (Figure 1).

isolating barrier 56 and the insulating cross bar 206. The chimney 282 which registers with opening 201 is a passage located above a portion of the arc chute of the circuit breaker Hi providing an escape path for the arc gases formed during circuit interruption. The are chute with which the arcing chimney 292 cooperates is described in the above-mentioned application Serial No. 721,648 filed January 11, 1947.

In Figure 8 we have shown a plan View of the bottom wall 61 of the compartment. Bottom wall 6'! is provided with a side guide 2H1 secured hereto in any suitable manner for receiving the wheels IUI of the circuit breaker truck when they are inserted into the circuit breaker compartment.

Opening 2!: is provided in order to provide access for the incoming cables or distribution bus network. Additional guide members 2l3 for the Wheels lili may be provided in order accurately to position these wheels, the said guide 2| 3 (Figure 3) being secured in any suitable manner as by welding or otherwise to the lower re-enforcing elements i5la of the compartment.

In Figures 9 and 9a are shown a front view of the front door panel 68 including the hinges 69 which facilitates attachment and the screws 19 which secure the door closed. We have also shown in detail the smaller door 62 for opening 55 to provide access to the racking and manual operating elements of the circuit breaker, showing also the hinges 53 securing the hinged panel or small door 62 on the main door 68 of the lock 64. The front door or panel 63 of Figure 9 also carries a stationary latching element 220 on the interior thereof (see also Figures 1, 2, and 13). I The function of this stationary latching element which is in position Whenever the door 68 is closed will be described in connection with the specific operating elements of the compartment and also in connection with the description of Figures 12 and 13.

In Figures 10 and 10a are shown rear and end views, respectively, of the back panel 65, which may also be hingedly secured in any suitable manner to the back of the compartment by means of hinges 225 secured to flanges of the compartment and locked in place by the securing means including the bolts 226. The back panel is provided with bottom louvres 22'! and top louvres 228 to provide for ventilation of the compartment 23.

In Figures 11 and 11a we have shown elevation and end views, respectively, of the isolating panel or barrier l8 having the openings 3|, 31 for the upper disconnect elements and the openings 31, 31 for the lower disconnect elements. The lower portion of the isolating barrier I8 is provided with an opening 230 for the ground connections 98 leading to the grounding bus (not shown) The isolating barrier I8 is provided with recesses 232, 232 at the corners in order to clear the channel elements 150, [5! on each of the side walls.

In Figure 12, we have shown a front view looking into the front of the compartment with the circuit breaker l0 removed from the compartment and showing specifically the safety shutter back panel 250 (Figure 13) pins 28l on each side of the circuit breaker 10 which ride against the under side of the bar 213 in the stationary cubicle. Bar 213 is pivotally connected at its front by the pin 283 carried by the side Wall of the compartment so that bar 213 may rotate up and down between the solid and dotted line position of Figure 13.

When the circuit breaker truck is in position in the compartment as shown in Figure 13, then pin 20! supports the bar 213 in the up position, thus pushing the safety shutter 250 to the up position where openings 3! and 3? in the isolating barrier [8 are accessible. As the truck 10 is withdrawn the pins Zj8l riding beneath the arms 273 continue'to support the same even past the test position until the circuit breaker truck is approximately half withdrawn from the compartment. At this time, the pins 23! pass beneath the chamfered surface 285 of the arms 213 on each side permitting the arms [13 to drop down to the dotted line position of Figure 13; both arms rotate about their pivots 283. links 27! to drop down thereby permitting the isolating barrier to drop so that section 25! of the isolating barrier 2356 covers the aligned openings 3! and section 252 of the isolating barrier 2558 covers the aligned openings 31. chanical shut off mechanism for the openings is thereby provided to isolate the disconnect contacts 21 and 35 which would otherwise be accessible.

The racking member hereinafter specifically described in connection with Figures 15 to 19 is provided with a latch member 300 on each side pivotally mounted at 30! on the side wall. The latch member 300 on each side is provided with an over-center tension spring 302 connected between pin 303 on one side of the pivot 30! on the latch member 300 and the lug 354 secured to the compartment wall on the other side of the pivot 3i The tension spring 302 is thus an over-center spring which will maintain the latch' 306 in the upper latching position shown by the solid lines of Figure 13 or in a down unlatched position shown by the dotted lines in Figure 13. The latch member 300 is provided with a latching detent 305 which engages the cross bar 30'! of the racking mechanism to prevent accidental displacementof the circuit breaker outwardly within the compartment as long as the latch member 300 is in the upward position. Latch member 300 is maintained in the upper position by the safety latch 226 on the inside of the front door 68. When the door is closed, safety latch 22;; is positioned under the latch member 3930 to prevent the latch member 300 from accidentally dropping down and thereby releasing the cross bar 361'; this prevents accidental removal of the cross bar 30? toward the front end of the compartment and bars movement or the circuit breaker 10 toward the front of the compartment except when the latch see is released intentionally by the operator.

' As seen in Figure 12 as well as in Figure 1, the "horizontal channel members Hi! on each :side carry a track member 320 secured thereto by bolts 322 which pass through the nuts 323 welded inside the channel ii The track membersprovide an appropriate guide or track from the intermediate wheels Hi3 and I04 on each side. An additional retaining flange or ledge 325 is provided on each side at th interior end of the track members 320 secured to the reinforcing member 170, Him by the bolts 32%. The rear wheel I03 'on each side of the circuit breaker truck H! moves in under the retaining flange 325. This acts to prevent vertical upward displacement owing to circuit interrupting conditions within the'cireuit breaker "iii itself and ensures that the circuit breaker will remain stationary during interrup-' 'tion: of severe overcurrents. I

It will benoted from Figure 15 that the bar This permits the A me- 400 supports the guide wheels I03-l03a which in turn ride on the guide tracks 320-420. When the breaker has been rolled into th enclosure as far as shown in Figure 17 and Figural-the bar 400 is capturedin the detent 306 of the latch member 300. This prevents further movement of the breaker in either direction except by tuming the racking screw 405 which is accomplished by inserting a crank in the front end of the racking screw at 406.

Since the bar 460 is held stationary by the latch member 300 rotation of the racking screw 405 in the clockwise direction will caus the breaker to move into the connected position due to the pressure of the shoulder 3 of the racking screw 405 against the cross member 412.

As the mechanism is racked into position the pin SSI cooperates with the interlocking trip cam 33!) and rotates the tripper bar extension 92 to the trip position thus opening the circuit breaker and assuring that the breaker cannot be racked into the operative position with the circuit breaker contacts closed. The reverse of this condition exists when the circuit breaker i0 is racked out. As soon as the racking out operation is started pin 33l cooperates with interlooking tripper cam 330 and trips the circuit breaker l0 beforethe disconnect contacts 3434' have separated (Figure 2).

Further elements of the racking mechanism correspond to the device shown and described in application Serial No. 721,648 filed June .11, 1947.

Our invention makes possible:

1. Use of individual assemblies.

2. Utilization of mass production methods.

3. Utilization of parts which may readily be stored in a flat condition.

4. The arrangement of a circuit breaker switchboard so that elements of parts may be readily'added thereto.

5. Arrangement of enclosed switchboard for 59,000 and 100,000kva. breakers.

6. Arrangements of switchboards so that not only additional structures may be added to include additional circuit breaker but also so that transformers and instrument casings ,may be added conveniently.

In the foregoing, we'have described our invention solely in connection with specific illustrative embodiments thereof. Since many variations and modifications of our invention will now be obvious to those skilled in the art, We prefer to be bound not by the specific disclosures herein contained but only by the appended claims.

We claim:

1. In a switchboard structure composed en-' tirely of substantially flat members forming the top, bottom, sides, back and partition walls, predetermined ones of said Walls having reinforcing ribs secured thereto and forming brackets, securing members for fastening said brackets to adjacent wall members, the side wall members having reinforcing ribs extending from adjacent the front towards the rear thereof and forming a track on which a circuit breaker is racked into and out of said wall, the side wall intermediate two adjacent walls acting as a common right and left wall for said adjacent cells andhaving said ribs symmetrically located on both surfaces thereof.

2. In a switchboard structure composed entirely of substantially flat members forming the top, bottom, sides, back and partition walls, predetermined ones of said walls having reinforcing ribs secured thereto and forming brackets, 

